Funding is requested for the continued support of the NIEHS Center at Vanderbilt University, which has been in existence and continuously supported by the NIEHS since 1967. The scientific base is the Center in Molecular Toxicology, an interdepartmental unit of investigators drawn from several departments in the School of Medicine and the Department of Chemistry. Currently, there are 16 named Center Investigators in the program from the Departments of Biochemistry, Chemistry, Medicine, and Pathology. These Center Investigators lead the programs, and the influence of the Center is extended to a larger base at the institution and in the community through collaborations and sharing of expertise. Current Research Cores include (i) Enzymatic Oxidation and Conjugation, (ii) Oxidative Damage, (iii) DNA Damage and Mutagenesis, (iv) Mechanisms of Cell Signaling, and (v) Structural Biology. Each Research Core is led by a Center Investigator and involves projects of Center Investigators and others. Service Core Facilities include (i) NMR and Crystallography, (ii) Mass Spectrometry, (iii) Proteomics, (iv) Molecular Recognition, and (v) Cell Biology. Other units include Administrative, Director's Office, and New Investigators. The Community Outreach and Education Program developed considerably during the course of the previous grant period and will be expanded further. The Center grant also supports a Pilot Project program, seminars and symposia, and other items aimed at strengthening programs at Vanderbilt relevant to environmental health science research. During the current grant period, four Center Investigators were recruited to Vanderbilt. A strong toxicology training program is in place. Major interactions at Vanderbilt involve the Division of Clinical Pharmacology, the Vanderbilt-Ingram Cancer Center, the Clinical Nutrition Research Unit, the Middle Tennessee Poison Control Center, and other programs. The overall focus of the NIEHS Center at Vanderbilt is basic chemical and biological aspects of molecular toxicology, with an emphasis on relevance to human health.